Broker for small-time options trades

My broker suddenly changed the margin rules today. We now need equity with margin value (essentially, equity exclusive of option value) to be > $2K to initiate trades. My account is several thousand dollars, but all but $1.5K of that is tied up in options, so I now can't buy anything.

Is this a Fed or SEC rule? It essentially means that people who trade only options, even all long options, have to keep at least $2K of cash in the account.

There is (or was, I'm trying to recall from my stockbroker days...) a federal reg that states that all margin accounts must be at least 2K. I'm pretty sure that is the case regarding the type of account (margin), not necessarily what is held in it. I don't know if that is the status of your account, but that might be the problem. The $2000 excess cash isn't how I remembered it, though.
Jessie